Among the pests of indoor plants, only thrips can compete with scabbards in perseverance and deceit. They are only noticed when they are widespread. Hundreds of species are difficult to distinguish among themselves, but all thrips attack plants equally and amazingly quickly. The sooner measures to combat them begin, the better, because these insects doom the plant to depletion and a rapid loss of decorativeness and leaves and flowers. Their invasion of the plant collection is rapid. And you should be prepared for the fact that it is very difficult to fight thrips without radical methods.
How to get rid of thrips on indoor plants? Farmer Burea-Uinsurance.com houseplantacademy
What are thrips?
It is usually possible to notice thrips and understand that they are the ones harming the plant, usually only by traces – serious lesions on the leaves. This is one of the most difficult insect pests to diagnose, which, in addition to indoor plants, is dangerous for horticultural crops. There are many reasons for the “secrecy” of thrips. Different appearances in more than a hundred species and their small size do not make them easy to recognize with the naked eye.
TRIPS (Thysanoptera) – a special order of microscopic insects that are not fully transforming. On average, the length of thrips is about 0,5-2 mm, sometimes they are even smaller, but very rarely exceed 5 mm (and such giants are almost never found in rooms). Slender legs with teeth and bubble-shaped suckers, a piercing-sucking mouth apparatus, two pairs of thin fringed porches and an elongated body are difficult to see without a magnifying glass. Thrips fly poorly, but run fast, and their movement usually gives them away.
Thrips are colored differently. On indoor plants, you can meet black, brown and gray insects. But to diagnose the exact kind – brown floral western, brown variegated, transparent whitish decorative thrips and dozens of others – optional. Differing outwardly, they harm plants in the same way and require a similar control strategy.
Thrips go through five stages of development from eggs to adults and are capable of giving up to 15 generations of offspring per year. In typical indoor conditions – temperatures above 20 degrees – their number on a plant can double every 2-5 days.
These pests are especially common in the subtropics and tropics, greenhouse and indoor culture, where they multiply surprisingly quickly in warmth and are almost indestructible in closed conditions. It is believed that they are especially fond of bulbous, tuberous and orchids, but they do not mind eating any houseplant.
Why are thrips dangerous?
Thrips love flowers, but in indoor plants it is much easier to recognize them by their leaves. Pests do not sit on one plant for long, quickly move to neighbors, hide in the soil and are almost invisible.
Feeding on the sap of a plant from the larval stage to death, thrips not only suck out the vitality from it, but also infect with their secretions. They pierce the leaf tissue, leaving subtle light, whitish-cream dots and streaks that merge into discolored, chaotic patterns. Spots, strokes, stripes are easier to see on the seamy surface, on the top they seem to be an inhomogeneous silvery-milky-matte bloom.
The dying off of tissues at the puncture sites and the effect of an uneven bluish film is not immediately evident, but gradually expanding patterns cover an ever larger area and lead to serious lesions. Dry spots and patches appear on the leaves, they turn brown and dry out. On flowers, punctures of thrips are less noticeable, but they deform much faster. Thrips do not spare even the shoots, which also gradually become covered with small spots and bend.
The depressed state of the plant, growth arrest, rapid flowering, dying off and shedding of leaves and flowers are a sad result of thrips’ vital activity.
The best assistant in diagnosing thrips is a magnifying glass. If suspicious light “scuffs” and uneven bloom are noticeable on the leaves of a plant, it is worth examining them through a magnifying glass to notice insects that are almost constantly in motion.
When they say that thrips cannot be exterminated, but can only be controlled, they usually mean winter gardens and greenhouses, where it is really very difficult to cope with insects. It is worth fighting in the rooms with this ravine, because the chances of success are much higher.
Simple methods of dealing with thrips
If you can try to cope with other insect pests with household, improvised means, then they almost never help with thrips, only delaying the beginning of an effective fight and allowing them to spread even more. Washing leaves, infusions, decoctions – experiments that can cost you the loss of a plant.
A strong soapy infusion, evenly applied to the leaves, reduces the number of larvae and adults, but does not allow to get rid of them altogether. Many flower growers experiment with fragrant water, onion and garlic infusions, decoction of tobacco, celandine and yarrow. But such funds can only help partially and at the earliest stages of distribution.
Even simpler steps are the first and very important steps on the path to success in the fight against thrips:
- If you find signs of pests and you suspect that thrips have settled on the plants, you need to isolate the affected plant as soon as possible and thoroughly clean the windowsill and all surfaces nearby. It is impossible to stop thrips without quarantine.
- Plants that tolerate wet leaves should be thoroughly washed with a warm shower, trying to keep the leaves under soft streams longer.
- On orchids and crops with fleshy leaves, it is possible to trim out damaged tissue to healthy tissue by treating the wounds with wood ash. For crops with delicate or small leaves, it is best to remove heavily damaged leaves entirely, because they will not recover anyway.
After the initial treatment, it is worthwhile to wisely approach the choice of insecticidal agents.
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The safest option is insecticides
Pesticides are difficult and dangerous to use at home, but in the case of such rapidly multiplying opponents, they are the fastest, most reliable and effective method of treatment.
To combat thrips, both highly specialized insecticides and systemic preparations are suitable:
- repellent aerosols, if, in addition to mosquitoes, midges and ticks, thrips are also included in the list of species.
Usually, 2-3 sprays are carried out from thrips with an interval of 10 to 12 days, with the plant being covered with a cap or placed in a bag for isolation. But there are no universal recipes. It is worth using insecticides strictly according to the manufacturer’s instructions, especially carefully observing the dosage, recommendations on safety measures and the frequency of treatments. Improvisation is inappropriate here, because even 1 day of difference or slightly increased concentration can lead to serious consequences.
After starting the treatment with insecticides, it is worth carefully removing and replacing the top layer of the substrate in which these insects often hide.
A unique feature of thrips is their excellent adaptability. They easily develop resistance to insecticides, so it is better to change the drugs used on a regular basis, especially ifboots are carried out prophylactically.
Biohazards are a slow but sustainable alternative
Few of the flower growers use pesticides for indoor plants without remorse. Taking all precautions will not make it safer to fight thrips. Finding a natural, harmless and effective control method is difficult. But there is an alternative to conventional insecticides – biological agents.
Biological products based on entomopathogenic fungi are especially effective. Classic preparations for thrips – Fitoverm, Bitoxybacillin, Bionim, Carbion, Boverin, Antitrips, Aktofit.
Every manufacturer of biological products for indoor plants has their own systemic bioinsecticides, effective against these “unstoppable” insects. Spraying will need to be done more often and for longer, but it will not harm you or your pets.
Unfortunately, thrips multiply too quickly to be fought with biological enemies. Biocontrol using predatory insects at home is not applicable, it is used only on an industrial scale.
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Prevention is easier to fight
The difficult fight against thrips makes everyone regret the untimely measures taken. They are often “introduced” to houseplants with purchased annuals, seedlings and new flowers, even if they get into the house for only a few hours. Quarantine measures, the lack of “contact” of seedlings with houseplants and the allocation of several weeks to adapt and isolate newcomers is the most important step in order to prevent the spread of the ubiquitous thrips.
There are other measures that will help, if not prevent the appearance of thrips, then reduce the harm from them to a minimum:
- buying a substrate from trusted producers (thrips are introduced with soil only a little less often than with plants);
- protecting plants from extremely dry air and maintaining optimal performance for certain species;
- regular warm shower (for all plants for which it is permissible);
- the use of glue traps that lure aphids, thrips and other insects and allow them to be quickly identified.
But no amount of measures can replace vigilance – regular inspection of the bushes, especially the back of the leaves and shoots. Traces noticed in time will allow to take measures in the early stages, preventing the spread of thrips throughout the collection. After all, the earlier the struggle begins, the greater the chances of success.